This invention relates to a radio paging receiver and, in particular, to a radio paging receiver with an error indicating function of overwriting faulty message data with error indication data when a message is displayed during a radio calling operation.
An existing radio paging receiver of the type memorizes message data and error indication data to overwrite the message data. In accordance with a predetermined program, the message data are read and judged for presence or absence of an error. In presence of the error, the error indication data are read to overwrite the message data before the message data are delivered. Then, the message data with or without the error indication data are displayed.
The radio paging receiver mentioned above receives an external radio communication signal containing the message data addressed to the receiver and demodulates the radio communication signal into a digital signal. The digital signal is analyzed into word data to detect an address destined to the receiver and to acquire the message data following the address. The above-mentioned analysis is carried out by establishing bit synchronization using a preamble of the digital signal and by establishing word synchronization by detecting a synchronization signal contained in the digital signal.
There are various previous techniques related to the radio paging receiver having such error indicating function. For example, Japanese Unexamined Utility Model Publication (JP-U) No. 64-48949 (48949/1989) discloses a radio paging receiver with a display function, in which error symbol indicators are provided below a message display zone in one-to-one correspondence to message characters and, if an error is present in received message data, one of the error symbol indicators corresponding to an error character is lightened. Japanese Unexamined Patent Publication (JP-A) No. 6-204937 (204937/1994) discloses a radio paging receiver in which, upon occurrence of an error in a received message or upon failure in message reception, an error content and contact address information are explicitly displayed.
In each of the existing radio paging receivers mentioned above, such error indicating operation upon message display is carried out as specified by a predetermined program. Therefore, the content of error indication can neither be changed nor diversified.
Specifically, necessity of the error indication upon message display is caused by various reasons, for example, due to system sensitivity or sender""s mistake in message entry. On the side of a recipient or a possessor of the receiver, it is impossible to identify a specific reason. Therefore, a single kind of error indication is used in the existing radio paging receivers for the purpose of simply informing the recipient that the presence of the error is indicated.
Such a single kind of error indication is unfavorable because the receiver is used in various situations. For example, when the recipient recognizes that the error is susceptible to occur because of positional relationship between a paging system and the receiver, error indication is too conspicuous (a narrow reception area is exposed). In this event, it is desired to perform the error indication in a moderate or less conspicuous manner. On the contrary, if message display is very important for the recipient, the error indication is also significant. In this case, it is desired to perform the error indication in a more conspicuous manner. Thus, the content of the error indication is desired to be altered or diversified.
If the paging system supports multiple languages, the following problems will arise. For example, Hindi and Arabic languages contain many characters with horizontal lines. In fact, the error indication by the use of underlines or double canceling lines are effective in English characters, Japanese kanji characters, Chinese kanji characters, and so on. However, with respect to Hindi and Arabic languages of the above-mentioned nature, it is difficult to judge whether a particular character with an underline or a double canceling line is a normal character or a faulty character with error indication. Under the circumstances, it is desired to realize the function of performing variable error indication adapted to different natures of the multiple languages.
However, in the existing radio paging receiver with the function of performing a single kind of error indication as described above, the content of the error indication can not be altered even if it is desired in correspondence to the degree of significance of error indication or in order to optimize the error indication depending upon the nature of the language. Thus, the demand for a variety of error indication can not be met.
It is a technical object of this invention to provide a radio paging receiver which enables error indication to be easily altered and therefore diversified so as to assist a user in handling.
According to this invention, there is provided a radio paging receiver comprising a data memorizing section for memorizing message data and error indication data to overwrite the message data, a control section for detecting presence or absence of an error in the message data, overwriting the message data with the error indication data in presence of the error, and transmitting for message display the message data alone or the message data overwritten with the error indication data, a display section for displaying the message data alone or the message data overwritten with the error indication data, a code program setting section for setting a program for entering the error indication data in correspondence to code identification in response to an indication request, and an error identification memorizing section for rewritably memorizing the error indication data in correspondence to the code identification. The control section makes the error identification memorizing section preliminarily store the error indication data in correspondence to an ID code for the code identification specified by the program.
In the above-mentioned radio paging receiver, the control section makes the error identification memorizing section store the error indication data in a manner such that different contents are stored at different addresses, respectively.
In the above-mentioned radio paging receiver, the control section reads, when a power supply is turned on, the error indication data from the error identification memorizing section and makes the data memorizing section memorize the error indication data.
In the above-mentioned radio paging receiver, the data memorizing section comprises a message data memory for memorizing the message data for use in error detection, and an error indication data memory for rewritably memorizing the error indication data. The control section reads the message data from the message data memory upon message display and, in presence of the error as a result of error detection of the message data, reads the error indication data from the error indication data memory to overwrite the message data before transmission of the message data for message display.
In the above-mentioned radio paging receiver, the control section reads, when a power supply is turned on, the error indication data from the error identification memorizing section and makes the error indication data memory memorize the error indication data.
The above-mentioned radio paging receiver further comprises a radio receiving section for receiving an external radio communication signal including the message data addressed to the receiver to demodulate the radio communication signal into a digital signal, and a decoder for analyzing the digital signal into word data to detect an address destined to the receiver and delivering to the control section the address thus detected and the message data following the address.
In the above-mentioned radio paging receiver, the decoder analyzes the word data by establishing bit synchronization using a preamble of the digital signal and by establishing word synchronization by detecting a synchronization signal contained in the digital signal. The control section makes the error indication data memory memorize the address destined to the receiver.